On 20 August 1837, he entered The Society of Mary Seminary at Lyon, France, and made his Profession in February 1840. He worked with Lay Organisations, promoting Devotion to The Blessed Virgin Mary and to The Eucharist, particularly in The Forty Hours Devotion. He rose to the position of Provincial of The Society at Lyon in 1844. His new responsibilities included charge of The Third Order of Mary, a Lay Group Dedicated to Marist spirituality and to promotion of The Christian Family. Saint John Vianney was a member.

His Eucharistic spirituality did not spring full-grown from some mystical experience, but progressively. As Visitor-General, Eymard travelled throughout France to inspect the various Marist Communities. He became familiar with the practice of sustained Eucharistic Worship during a visit to Paris in 1849, when he met with members of The Association of Nocturnal Adorers, who had established Exposition and Perpetual Adoration of The Blessed Sacrament at the Basilica of Our Lady of Victories.

After Praying at The Shrine of Our Lady of Fourviere, on 21 January 1851, Eymard moved to establish a Marist Community Dedicated to Eucharistic Adoration. However, his desire to establish a separate Fraternity promoting Adoration of The Blessed Sacrament was not seen as part of the Charism of The Marists.

His Superiors disapproved, Transferring him to The Marist College at La Seyne-sur-Mer. Eventually, Eymard resolved to leave The Society of Mary, to begin his new Religious Congregation with the Diocesan Priest, Raymond de Cuers.

On 13 May 1856, the Paris Bishops consented to Eymard's Plans for a ‘Society of The Blessed Sacrament’. After many trials, Eymard and Father de Cuers established Public Exposition of The Blessed Sacrament in Paris on 6 January 1857 in a run-down building at 114 rue d’Enfer (which, literally, meant ‘Street of Hell’).

The Congregation of The Blessed Sacrament began working with children in Paris to prepare them to receive their First Communion. It also reached out to non-practicing Catholics, inviting them to repent and begin receiving Communion again. Father Eymard established a Common Rule for the members of The Society and worked toward Papal Approval.

A second Community was established in Marseilles, in 1859, and a third, in Angers, in 1862. Blessed Pope Pius IX granted a Decree of Approbation in June 1863. Eymard was a tireless proponent of frequent Holy Communion, an idea given more authoritative backing by Pope Saint Pius X in 1905. [Editor: Prior to the beginning of the 20th-Century, Holy Communion was normally only received by Catholics a few times a year, especially at Eastertide. Pope Saint Pius X promoted daily reception of Holy Communion, given that one was in a State of Grace in order to receive it.]

On 10 January 1969, Blessed Pope Paul VI issued a Letter to The Superior General, Father Roland Huot, S.S.S., of The Congregation of The Blessed Sacrament, lauding the most excellent function of Adoration of The Blessed Sacrament Outside Mass, declaring all those who do so make their Eucharistic Adoration "in the name of The Church" https://www.ewtn.com/library/PAPALDOC/P6ADORE.HTM This concession is included in the revised Roman Ritual, Holy Communion and The Worship of The Eucharist Outside Mass, No. 90 in The Editio Typica.

By DECREE of The Congregation for The Sacraments and Divine Worship, dated 9 December 1995, SAINT PETER JULIAN EYMARD, PRIEST, was inserted in The General Roman Calendar with the Rank of Optional Memoria.

Font and fullness of all Evangelisation and striking expression of The Infinite Love of Our Divine Redeemer for mankind, The Holy Eucharist clearly marked the life and pastoral activity of Peter Julian Eymard. He truly deserves to be called an outstanding Apostle of The Eucharist. In fact, his mission in The Church consisted in promoting the centrality of The Eucharistic Mystery in the whole life of The Christian Community.

The French sculptor Auguste Rodin received counsel from Eymard when Rodin entered The Congregation as a Lay Brother in 1862, having given up art after the death of his sister. Eymard recognised Rodin's talent and advised him to return to his vocation. Rodin later produced a bust of Eymard.

He was declared Venerable in 1908, Beatified by Pope Pius XI on 12 July 1925, and Canonised by Pope Saint John XXIII on 9 December 1962. (Also Canonised with Saint Eymard were Servite Priest Anthony Mary Pucci (1819–1892) and the Capuchin Lay Brother Francis Mary of Camporosso (1804–1866)). Saint Peter Julian Eymard's Feast Day is Celebrated in The Roman Catholic Church on 2 August. Pope Saint John Paul II named Saint Eymard "Apostle of The Eucharist".

Saint Peter Julian Eymard is a Patron Saint of Saint Jean Baptiste Catholic Church in New York City. A Shrine to the Saint in the Church contains a Reliquary of the Saint. He is recognised as a major contributor to 19th-Century French spirituality.